1.. Field
The present invention relates to toner, a development agent, and an image forming apparatus.
2.. Background Art
Printers and multi-functional printers (MFP) using image forming apparatuses employing electrophotography have been required to be environmentally friendly in recent years.
Attempts are being made to achieve that goal, such as reducing the amount of carbon dioxide emissions by consuming less power and becoming carbon neutral by using biomass raw materials.
Against this backdrop, using toner that is fixed at lower temperatures is desired.
One known way to achieve such toner is to add a crystalline resin typified by a crystalline polyester resin that melts instantly upon heating during fixing to the binder resin for use in the toner.
In addition, JP-H04-24702-B (JP-S62-070859-A) and JP-H04-24703-B (JP-S62-070860-A) disclose methods of using a crystalline resin as the main component of the binder resin.
In general, toner contains a releasing agent such as wax to impart releasability to the toner to facilitate separation from a fixing member during fixing.
Such a releasing agent is also required for toner having a crystalline polyester resin as its main component.
For example, hydrocarbon-based wax, such as paraffin wax or microcrystalline wax, is widely used as the releasing agent.
However, when such wax is used, material attaches to and accumulates on a recording medium discharging member provided downstream of the fixing member, which can damage the fixed image.
If ester wax having an ester bond unit in its molecule is used, such material accumulation is not significantly noticeable but the releasing ability suffers, which tends to result in winding-round of the recording medium during fixing.
For example, JP-2010-77419-A discloses using crystalline particulates having a particular storage elastic modulus and loss elastic modulus as resin particulates having excellent low-temperature fixability and clumping resistance while also using an aliphatic acid ester such as behenyl behenate as the releasing agent.
However, problems persist in the form of contamination of the discharging member after fixing and poor fixing releasability particularly in the case of thin paper.